System and method for controlling pump

Abstract

Systems and methods including a motor or electromagnets to control the movement of one or more pistons in a pumping chamber. The pumping chamber may include a pump inlet and a pump outlet in fluid communication with the pumping chamber. Surfaces on a piston or pumping chamber may include hydrodynamic bearing surfaces.

Description

STATEMENT OF RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 12 / 425,042 filed on Apr. 16, 2009. This application is a continuation of U.S. application Ser. No. 12 / 985,715 filed on Jan. 6, 2011, which is a continuation of U.S. application Ser. No. 11 / 773,740 filed on Jul. 5, 2007, which depends from U.S. Provisional Application Ser. No. 60 / 806,667 filed on Jul. 6, 2006.FIELD OF INVENTION[0002]Embodiments of the present invention generally relate to pumps. More specifically, and not by way of limitation, embodiments of the present invention relate to positive displacement pumps for the circulation of fluids.DESCRIPTION OF RELATED ART[0003]Many natural and manmade fluids contain molecules that can be damaged or destroyed by excessive shearing strains or stagnation that can occur in devices that attempt to pump these fluids. Fluids containing molecules with high molecular weights such as proteins, long stranded synthetic polymers, DNA, RNA, or f...

AI Technical Summary

Benefits of technology

The invention is about a new type of pulsatile assist device that improves upon previous devices. It allows for a variable stroke volume through variation of fluid energy with drive piston speed, which can reduce or eliminate fluid hammer effects. It also allows for a reduction of the pumping chamber size without reducing the ejected stroke volume. The invention can be controlled to produce a precise sensitivity to preload and afterload, restoring the native Frank Starling response observed of a healthy heart with a VAD.

Problems solved by technology

Many natural and manmade fluids contain molecules that can be damaged or destroyed by excessive shearing strains or stagnation that can occur in devices that attempt to pump these fluids.

Fluids containing molecules with high molecular weights such as proteins, long stranded synthetic polymers, DNA, RNA, or fluids such as blood, which contain concentrations of delicate cells, are especially susceptible to being compromised by many conventional pumping techniques.

The shearing stresses that can arise at these velocities can strain larger fluid molecules until they break, leading to destruction or undesirable alteration of the pumping medium.

This phenomenon, known as hemolysis, is an issue in the field of artificial blood circulation because the releasing of hemoglobin into the blood stream can cause kidney failure in patients who receive this blood.

Images